Automatic pilot



April 18, 1950 J. c. MALEN 2,504,139

AUTOMATIC PILOT Filed June so, 1945 I s Sheets-Shet 1 INVENTOR. Jar/y C Ma/en A TTORNL'Y April 18, 1950 c, MALEN 2,504,139

AUTOMATIC PILOT Filed June 30, 1945 Sheets-Sheet 2 5' FORE I 224/ I Arr I JD 24 /e 19a, 24

I 50b I I 23a Fig.3

:0 INVENTOR.

/ Jar/g C. Ma/en MLW ATTORNEY J. C. MALEN AUTOMATIC PILOT April 18, 1950 3 Sheets-Sheet 3 Filed June 30, 1945 AFT INVENTOR. Jar/y C. 446/677 M LW ATTORNEY I FORE Patented Apr. 18, 1950 OFFICE AUTOMATIC PILOT J arly C. Malen, United States Navy Application June 30, 1945, Serial No. 602,638

7 Claims.

This invention relates to automatic pilot systems of automatically maintaining a ship or aircraft on a steady course.

One object of this invention is to provide a simple and inexpensive mechanism for attachment to the steering mechanism of a ship or aircraft which will be automatically responsive to course changes and which will automatically actuate the steering mechanism to compensate for such course change.

Another object is to provide an inertia type of automatic pilot.

Still another object is to provide an automatic pilot that is responsive to changes in course and elevation when installed in an aircraft.

Further objects and advantages of this invention as well as its construction, arrangement and operation will be apparent from the following description and claims in connection with the accompanying drawings, in which,

Figure 1 is a diagrammatic illustration of the automatic pilot system according to this invention and as applied to a standard electrically operated steering mechanism,

Fig. 2 is a side elevational view partly in section showing the automatic pilot mechanism,

Fig. 3 is a plan view of the pilot mechanism shown in Fig. 2,

Fig. 4 is a side elevation partly in section of a modified type of automatic pilot adapted for use in an aircraft, and

Fig. 5 is a plan view of the structure shown in Fig. 4.

There is shown, in Figs. 2 and 3, the structure of the automatic pilot steering-control means constructed according to this invention. The control means comprises a bowl I filled with a suitable flotation liquid 2. A pair of diametrically opposed knife edges 3--3a project outwardly from the periphery of the bowl I as shown in Fig. 3, and seat in a pair of corresponding bearings 4-411 provided in the gimbal ring 5. A buoyant circular float B is fioatably supported in the bowl I by the liquid 2, and a centering pivot member 17 secured to the bottom of the bowl I and engaging pivot bearing 8 in float 6 positions the buoyant float 6 centrally within the bowl l. A plurality of radially disposed webs or fins 9 are secured to the bottom of float 6 and extend downwardly therei'rom into the fluid 2. These webs or fins serve to stabilize the float 6 against rotation in the floatation medium 2. The inside of the bowl I is highly polished to minimize friction between the liquid 2 and the bowl so that,

as the bowl I rotates with the ship or plane on (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) which is is mounted, the float 6 and the liquid 2 will remain stationary. A weight la. is secured insulated therefrom by an insulating strip II (Fig. 2). An electromagnet comprising an iron core l2 and a pair of separate energizing coils I3 and I4 is secured, as by clamp l5 and screws IE,"

to the periphery of the bowl I, with the core I2 normally in alignment with the bar 10, as shown in Fig. 3. The clamp I5 permits adjustment of the air gap I1 between the solenoid core I2 and the end of the control bar l0.

sides of the control bar as shown in Fig. 3.

Mounted on the periphery of the bowl I are a" pair of electrical conducting arms I9-I9a. The free ends of each of these arms extend into proximity to each of the electrical contact points I 8-4 to on the bar It as shown in Fig. 3. The

arms I9-I9a are mounted on insulating blocks 20-2011 which are each secured to the periphery of bowl I by clamping bolts 2I-2ia mounted inelongate slots 22--22a formed in the peripheralface bf the bowl. The bolt and slot connection enal les adjustment of the arms I 9-I 9a in relatiz n to the control bar I0.

The gimbal ring 5 is provided with a pair of diametrically opposed knife edges 5a-5b (Figs. 2 and 3) arranged at right angles with-respect to the knife edges 33a on the bowl I as shown in Fig. 3. The knife edges 5a5b are mounted in bearings 23-2311 on the supporting stand 24, which, in turn, is secured on the fore and aft line of the ship or plane. From the above description it can be seen that the bowl I is freely suspended in the support 24 so that it will remain substantially horizontal despite pitching, rolling or yawning of the ship or plane in which the support is mounted. The bowl I is free to rotate relative to the float 6 within limits because of the practically frictionless floatation medium 2,

so that rotation of the bowl I (as the ship or plane, is turned) .will not affect the stability of the,

steering mechanism comprises a compound-' wound motor 30 consisting of an armature 8|, a

series field 32, a shunt field 33, and a series re- A pair of elec-" trical contacts l8l8a are mounted on opposite r 3 sistance 34. The motor 30 is adapted to be run either as a motor to operate the steering mecha-.- nism (not shown) or as a generator in order to insure rapid braking of the motor when it is disconnected from the power source.

The armature 3| of motor 30 is normally connected across'load resistor 35 by means of a pair of solenoid operated switches 36-=-,3I*which are normally held closed by the springs 36b -3ll respectively. When the armature 3i is energized from the supply mains, as will later be described, the current through the solenoid coils 36a 3711 will open switches 36-3'l, disconnecting the armature from load resistor 35. the power" source is disconnected, coils 38 and Sla of;

switches 36-31 are deenergi'zed and these switches will close under the action or springs elto oppositepolesof these switches by leads t l and 44a- :as shown in; Figs 1-; and the switches armin:turn connected-by lea-d's tiiand titato the current-Supply maim- It can therefore be seen that closing either one otthe solenoid switches 41- or 4-2 will connect-the armature 3i across the supply; main (in; parallel-with the shunt field 33') and that the-direction of rotation or'the armature M- will depend onwhich; or these switches M or 42' is closed; Thearmature 3 is also-eonnected: by leads 4=3===43a to corresponding poles- KV=-,l;3a.- ofthe'fi-vepole double-throw switch 55". cdrresponding terminals4-3 an-deed" of switch-J6 arelin turn, connected td'so-lencid coil l3 of the electromagnet i2= on the pilot; in series with a variable resistance 41-.

vThe electrical condu'ctin'g arms te -Wm are cennetedi by leads 4-8-"-=48a;-to corresponding ter min'als 68" 48h" or switch- 46 through leads limit switches til -49a in series with the s'olen'oi coils mi and nu o'f switches- M and 4'2, respec: tiiieiyi- The springs lei-'5 and 426 normally hold M and 42? open closed' by the en 6; either of the solenoid coils" 41a or" limit switches which iaf set-tc itthemasimum 6f the rfi'ddr showlr) "n'trolbar m, (Fig; 1')" electrically connect siippiy s couriepush batten switch- 5 "connected in tne soieaciu can I circuit.-

' A hand qntr'q 53 fornianuaiiy control-ling'the stcerm motcr'sl is provided. Tl'ie'har'id Conner;

as illustrated rig; rccrisists cf't ne three conti on actuaticn of} the hand control lever 51. to

close contact 5'5- with eitherBSTor' 5t will close either solenoid switch 4! or 41 thereby actuating and controlling the rotation of the steering The operation ofthe automatic pilot in con- \3 on the fore and aft line.

junction with the steering mechanism is as follows:

Thev steering motor is mechanically coupled to the steering rudder (not shown) of the ship or aircraft and the automatic pilot shown in Figs. 2 and 3 is mounted by means of the mount 24 coincident with the fore and aft line of the ship J5 double push-button. switch 5| is manually closed,

thereby energizing solenoid coil M, which creates therieccss'ary flux in solenoid core IE to hold the control: bar ill centered between the conducting arms" t9-t9dz-- The ship can now be turned to a a desired course manually, and the control bar I U will be centeredin a neutralpositionspacedfrom arms it-liiaa The double push button switch 55 is now released, deene'r-gizing. the solenoid coil i4, and switch d5 is closed to downposition, whereby the automatic pilot will maintainthe ship the setcourse by actuating. the steering" motor controls ib-4 2 iii-response to course deviations, -in.- the followingmanner.-

' Shou-ldthe ship momentarily change course the inertia member of buoyant float 6 (Figs. 2

and'S) will-rotate relativetothe bowl Lthelatto! turning with the rotation of the-ship. This will cause the control-bar I E] to contact either one crthe arms i9l9w throughcorresponding; con

tacts l8 or- [8a. depending on the direction in which the ship isturnedl Assuming the ship has turned to the right with reference to the fore and aftline/, -Fig.- ii, the control bar l fl'will" contact arm 9- and an electrical continuous circuit will be established betweenthe supply main, lead 59, control bar in, contact {8; arm {9 and lead, :8,, energizing-- solenoid Ma and closing switch 4-l-.- Whenswitch H is closed, the armature 3! of the steeringmotor is connected comes the supply mainthrough leads 41-55 and M's- 45a, thereby causing it to rotate and apply the necessary amount of rudder to turn the ship back into the set course. At the same time,- solenoid coil l3 on electromagnet i2. is energized through 1' mean -sea setting fup a magnetic field which attracts the control bar It back intea centrally aligned position-spaced between conducting arms Iii-49a. as the ship swings back into a position corresponding with its set-coursethereby interrupting the circuit, stopping the steering engine,v and;- in turn deenerg-izing the solenoid coil l3;

sim-ilarly shouldthe ship swing. to the left, arm

911,- Would make electrical contact with the con trol armli'i} and: an electrical circuit would be set up through lead 48a, energizing the solenoid operated switch 42 through coil' 42a; and operating the steering engine armaturesi in an opposite direction to that previously described} thereby turning. the ship back to itsco-urse. At the same time the solenoid core [2- is again energized by coil-13' throughleads 4343a again toce'nter the controlbar It as previously described, thereby discontinuing the circuit. Bysuch intermittent action of the control bar" it), res onse to course deviations, the automatic pilot maintains, the ship on a. steady course. 7

The stability or the float 5 andconductingJbar' H! can be utilized to: maintain a plane in substantially level flight as well as in course accord ing to the modificationillustratedini igs. 4 and 5 of the drawings. In this modification a level flight control is attached to the aft portion of the pilot in alignment with the fore and aft line of the plane as shown in Figs, 4 and 5. A bracket 60 is secured to the mount 24 by the screws 5|. A pair of insulated brackets 62 and 63 are slidably mounted on the bracket t0 and a p'airof conduct-- ing arms 65 and 65a are secured to these brackets by screws 69. The arms 65-6511 project over the face of the bowl I and an electrical contact 66 is provided at the extremity of each arm. Secured to the control arm I and in electrical contact therewith is an ofiset contactor arm 61, a portion of which projects into the gap between conducting arms 65-65a, which are arranged in vertical alignment with and spaced from the contactor 61; A pair of electrical contacts G8-68 are provided on opposite faces of the contactor 61 for making electrical contact with the contacts 66. on the arms 65 and 65a.

The electrical conducting arms 65 and 65a, as well as the control bar II) are connected to portions of an electrical circuit (not shown) which controls the operation of the elevator mechanism on the plane. The pilot mechanism illustrated in Figs. 4 and 5 of the drawings is mounted in the fore and aft line of the plane opposite the course control electrical contacts, previously described. Assuming the plane has been levelled off at a specified altitude, any tilting of the plane from such path of level flight would result in either one of the arms 65 or 65a making electrical contact with contactor 61. Thus, if the plane were to nose down, arm 65 would meet contactor 61 and thereby close the necessary electrical circuit (not shown) to operate the plane elevates to restore the plane to a level keel. Similarly should the plane nose upwards arm 65a, contacting the contactor 61 would effect the controls necessary to operate the elevators in a reverse direction to thereby restore the plane to its original level path of flight.

It is to be understood that various modifications and changes may be made in this invention without departing from the spirit and scope thereof as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. An automatic pilot for dirigible craft comprising a support secured in the fore and aft line of said craft, an inertia member freely suspended I in said support and including a low-magnetic-retentivity element, electrical contact means on said element, electrical conducting means suspended from said support independently of said inertia member and spaced therefrom, electrical circuit means connecting said contact and said conducting means to a steering control means on said craft, said electrical conducting means being movable relative to said contact means upon deviation of said craft from its course, said relative motion causing said conducting means to engage said contact means to close said circuit and thereby actuate said steering control, and means cooperable with said element for disengaging said contact means when said craft is returned to on 1 course condition.

2. A pilot for automatically maintaining a ship or aircraft on course comprising, a support secured on the fore and aft line of said ship or aircraft, an inertia member freely suspended in said support, a control bar of permeable, low magnetic retentivity material mounted on said inertia mem-' ber,- electrical contact means on said control bar, an eiectromagnet and a plurality of electrical conducting means freely suspended in said support independently of said inertia member, said electromagnet being in alignment with said control bar, said electrical conducting means being in spaced relation from said contact means, electrical circuit means interconnecting said contact means and said conducting means to steering control means on said ship or aircraft and said electromagnet, said conducting means being movable relative to said contact means upon deviation of said ship or aircraft from its course, said relative movement causing said conducting means to en-. gage said contact means to close said circuit and thereby actuate said steering control and energize said ele'ctromagnet whereby it attracts said conducting bar from its contact position'into spaced relation from said conducting means.

3. A pilot for automatically controlling the steering mechanism of a ship or aircraft comprising, a support secured on a fore and aft line of the ship or aircraft, an inertia member freely suspended from said support with respect to pitch, roll and rotation of said ship or aircraft, a control bar of permeable, low magnetic retentivity material secured to said inertia member, electrical contact means on said control bar, an electromagnet and a plurality of electrical conducting means freely suspended from said support with respect to pitch and roll of said ship or aircraft but being fixed to rotate therewith, said electromagnet being normally in alignment with said control bar and said conducting means straddling said contact means on said control bar on opposite sides of said fore and aft line and being spaced therefrom, electrical circuit means interconnecting said contact and said conducting means with said steering mechanism and with said electromagnet, deviation of said ship or aircraft from its course causing corresponding movement of said conducting means relative to said contact means whereby one of said conducting means contacts said contact means to actuate said steering mechanism and thereby compensate for said course deviation.

4. A pilot for automatically maintaining aircraft having electrically actuated elevation control means in level flight comprising, a support secured on a fore and aft line of said aircraft, an inertia member freely suspended from said support with respect to pitch, roll and rotation of said aircraft, a control bar of permeable, low magnetic retentivity material secured to said inertia member, electrical contact means on said control bar, a plurality of electrical conducting means secured to support in alignment with the fore and aft line of said aircraft straddling said electrical contact means and being in vertical spaced alignment therewith, whereby tilting of said aircraft from its path of level flight results in movement of one of said conducting means relative to said contact means to contact the latter.

5. The pilot as defined in claim 4, further characterized by means responsive to disappearance of the tilting of said aircraft from level flight and cooperable with said control bar to break the contact between said one conducting means and said contact means.

6. An automatic pilot comprising a support, a bowl freely suspended in said support and being fixed to rotate therewith, an inertia member Certificate of Correction Patent No. 2,504,139 April 18, 1950 JARLY C. MALEN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 2, line 1, for the word is, first occurrence, read it; line 42, for yawning read yawing; column 3, lines 42 and 43, strike out leads 148-149a by and insert the same before 1imit in line 44, same column; column 6, line 59, before support insert said;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 22nd day of August, A. D. 1950.

THOMAS F. MURPHY,

Assistant Gammz'ssz'oner of Patents,

Certificate of Correction Patent No. 2,504,139 4 April 18, 1950 JARLY O. MALEN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 2, line 1, for the word is, first occurrence, read it line 42, for yawning read yawing; column 3, lines 42 and 43, strike out leads 148-149a by and insert the same before limit in line 44, same column; column 6, line 59, before support insert said; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 22nd day of August, A. D. 1950.

THOMAS F. MURPHY,

Assistant (lommz'ssz'oner of Patents, 

